The Greens want free primary healthcare for all children.
The idea of this state-funded largesse is to treat people earlier to keep them out of more-expensive hospital care, and there is some evidence to support this view.
Labour costs its primary care changes at $280 million a year, and claims the Government's increases in health funding have not kept up with the country's needs.
But the Government says it has managed efficiently in tight financial times, increasing health spending from $12.6 billion in 2009/10 to $15.6 billion this financial year - about $500 million a year including reprioritised spending.
New Zealand's spending on health rose by more than twice the average rate among countries in the Organisation for Economic Co-operation and Development from 2009 to 2011, according to OECD figures.
It was Labour in government a decade ago that introduced universal subsidies for primary healthcare, a sector in which state funding was previously more targeted.
Under Don Brash in 2005, National threatened to unwind the policy, but later relented.
Under Health Minister Tony Ryall, since 2008 subsidies have expanded for some but have been eroded by inflation for others. He has made the free-under-6s concept - introduced by Winston Peters in the late 1990s and achieved only partially under Labour - a widespread reality. More than 95 per cent of children in that age group now have access to free care, including after hours.
But there are stress cracks in primary care. Rises in patient fees permitted by district health boards since 2009 have exceeded inflation.
Labour cites a Statistics NZ brochure showing the average cost to adults for a GP visit has risen by 24 per cent under National, to $36.28 last year. No corresponding children's charge is given, but a Health Ministry survey found it was $21 in 2011/12 among children whose care attracted a fee, while for 55 per cent there was no charge.
A Child Poverty Action Group survey last year found the average cost for a child aged 6 to 17 to visit a GP during office hours was $24. Individual charges ranged from zero to $60.
After hours the average fee was $44, and the range from zero to $89.
The ministry's annual survey last year found 6.3 per cent of children had missed out on a GP visit because of the cost in the preceding year - up from 4.8 per cent in one year. Labour claims there was an increase for adults too; the ministry report indicates there may have been an increase, but it was not statistically significant.
Labour also claims there is a "rising number of people turning up to emergency departments because they can't afford to see a GP" - and there is some evidence at least of rapidly increasing demand at EDs although the reasons are not clear.
A doctor/manager admitted in papers for the Auckland District Health Board that, even before the annual surge caused by winter illness, its adult emergency department was "struggling" to meet the Government's six-hour target for managing patients.
"The ED is geared to manage 160 patients daily but in effect has been managing in excess of 200 patients regularly in recent months."
Mr Ryall's six targets - EDs, elective surgery, cancer treatment, immunisation, urging smokers to quit, and heart and stroke risk checks - mark out his main achievements.
The groundwork for the big increase in child immunisation was laid under Labour, but it is Mr Ryall's tight focus on headline targets - Labour calls it his "obsession" - that has driven change, especially in ED times and increased amounts of elective surgery.
The amount of elective surgery increased in most of Labour's nine years in power, but fell in some years.
Under National, elective surgery has surged. About 158,000 patients were treated last year, a 34 per cent increase in five years, which was far greater than the population growth rate. Further increases are promised, with an extra $110 million committed over four years.
Despite this, a survey for the health insurance industry estimated last year that 280,000 people were "in need of elective surgery".
The industry says the public system cannot cope and needs private sector help, partly because of an ageing population needing more surgery and the decline, triggered by the recession, in the number of people with insurance.
Mr Ryall's cancer target has reduced waiting times for treatment, and he has funded a four-year trial of bowel cancer screening in Auckland's north and west, building on an idea proposed by Labour.
Labour leader David Cunliffe has promised to build the Waitemata scheme into a national programme, at an initial cost of $14 million a year.
His party says New Zealand - which has one of the world's highest bowel cancer death rates - is lagging behind many developed countries in not having a national screening programme, which could save up to 180 lives a year.
National will wait for the Waitemata results before making a decision on a national programme.
Population health - covering the likes of obesity, healthy eating and exercise - is another area traditionally the heartland of Labour and the Greens.
But National has shored up many of its weaknesses here with schemes such as the rheumatic fever prevention programme and child immunisation improvements.
Huge changes have occurred on tobacco control, thanks to MMP, Maori Party co-leader Tariana Turia and Internet-Mana Party co-leader Hone Harawira.
The percentage of people who smoke had dropped to 15 per cent by last year, from 21 per cent in 2006. Tobacco tax increases, the retail display ban and the proposal for plain packaging have had wide support in Parliament.
Some public health practitioners have not fully recovered from National's rapid abolition of many of Labour's efforts to improve the country's food "environment". National's instinct is the educational approach rather than confronting the food industry, although many experts agree this is unlikely to reduce New Zealand's obesity problem - we are the third most obese of OECD nations.
Our adult obesity rate rose from 27 per cent in 2006/7 to 31 per cent last year. Child obesity rose from 8 per cent to 11 per cent.
Labour would pass the Public Health Bill, which gives wide powers to control the food supply to address diseases in which food is a factor.
The Greens would require all food and drink sold in schools to be nutritious and want a levy on "fizzy/soft drinks" that would later be imposed on "other products that cause significant health problems".
National, although opposed to regulating food for the sake of obesity, has adopted an Australian scheme that has won praise from one of the Government's chief public-health critics, Professor Boyd Swinburn.
The Budget in May committed $40 million for the Healthy Families initiative to operate for four years in 10 communities, including two in South Auckland and one in the city's west.
Professor Swinburn said the scheme in Victoria involved talking to school principals and other leaders about "how levers can be pulled to make it healthier for kids", such as by altering the food available.
Life-saving bowel checks welcomed
Cancer survivor Helen Christopher likes the idea of a national bowel screening programme.
"I think it's wonderful. Everybody should have that opportunity to be screened and be safe."
Now aged 67, Mrs Christopher, a married Hamilton grandmother and administration worker, was 63 when diagnosed with early-stage bowel cancer.
That would have put her in the initial age group for the national screening programme Labour has promised to establish by expanding the Waitemata trial scheme first into the Waikato and Otago/Southland health districts and later the rest of the country. The eligible group in the two new areas would start at 50-64 and later expand to the 50-74 range covered in Waitemata.
National says going nationwide is inevitable but doing so at present would be premature and risks creating a programme that harms patients.
It will wait for the results of the four-year Waitemata trial, due next year, before making a decision.
Mrs Christopher, an otherwise fit and healthy vegetarian, was afflicted by diarrhoea, which sometimes contained blood.
After a month of that, she consulted her GP, who conducted tests and referred her for a colonoscopy - an investigation of the large bowel, the colon, with a tiny camera and surgical instruments on a flexible tube. Growths called polyps were detected and removed in that and a similar follow-up procedure and cancer was diagnosed. A CT scan showed the cancer had not spread outside the colon.
She had surgery to remove the affected part of the colon, which was near where it joined the rectum.
Her small intestine was connected to an external waste-collection bag for seven months "to allow the bowel to heal" and to ensure there was no return of the tumour.
In a further operation, the bag was removed and the large and small intestines reconnected, minus the "offending" section.
No chemotherapy or radiation therapy was required.
"I had a check-up two weeks ago to say everything was clear; there's no sign of any cancer in the colon at all," Mrs Christopher said.
"I was lucky enough I had gone early enough to get something done at an early stage.
"Whatever anyone can do to save even one person's life, people should be encouraged to go and get screened.
"I tell people at work, if you have got any abnormalities, just go and get looked at. It's not going to go away. If you leave it, you lose your life."
The series
Yesterday: Welfare and social housing
Tomorrow: Education
Friday: Foreign investment, migration
For more information about election policies go here.
